Electric-circuit tester



1,636,707 w. F. ROBINSON ET AL ELECTRIC CIRCUIT TESTER July 26 1927.

Filfid March 1924 Z0 I If INELNTORS wr W 4 ATTORNEY.

Patented July 26, 1927.

UNITED STATES PATENT OFFICE.

WILLIAM F. aonmson AND FRANKLYN r. nonmson, or KANSAS CITY, nssounn nLnc'rmc-cmcurr TESTER.

Application filed larch 8, 1924. Serial No. 686,651.

Our invention relates to improvements in electric circuit testers.

The object of our invention is to provide a tester fortesting circuits, fuses, and incandescent electric lamps, which is simple, cheap to make, durable, not liable to get out of order, which any one can'easily and quickly operate .without danger, and with which it can be readily determined whether or not the lamp orfuse is in working order, and with which it may be quickly determined which fuse or fuses of a number are defective.

The novel features of our invention are hereinafter fully described and claimed.

In the accompanying drawing which illustrates the preferred embodiment of our invention,

Fig. 1 is a side elevation of our improved tester.

Fig. 2 is a front elevation of the same.

Fig. 3 is a rear elevation, partlybroken away, of the same.

Fig. 4 is an end View of the tester.

Fig. 5 is a diagrammatic view of the circuit employed. I

Similar reference characters designate similar parts in the different views.

1 desi nates a supporting member, preferably 0% insulating material, such as a flat piece of wood, having a handle 2 at one end, and provided at the other end with two arms on which are respectively telescopical- 1y fitted two contact members 3 and 4, which are each, preferably, tubular at their inner ends, and each of which is provided at its outer end with a contact tip 5, which is of conductive material, such as steel or other metal, as is each of the members 3 and 4.

On one-side of the supporting member 1 is mounted an electric lamp socket 6, which is adapted to have removably fitted therein a fuse plug 7 having therein the usual fuse 8.

On the opposite side ofthe member 1 is provided a lateral bracket 9 on which is mounted another electric lamp socket 10 adapted to have removably fitted therein, in the usual manner, an incandescent electric lamp bulb 11, asshown. The socket 10 is disposed, as shown, facing longitudinally with respect to the supporting member 1, so that the bulb 11 will be located wholly between and parallel with the longitudinal edges of said supporting member, the latter being imperforate in that portion adapted to extend across the lamp bulb 11. By

conserved and the bulb 11 is less' liable to' be struck by extraneous objects, than would be the case with the bulb at right angles to the supporting member.

Referring to Fig. 5, 12 designates a conductor connecting the contact member 3 with one terminal of the fuse 8, the other terminal of which is connected by a conductor 13 with one terminal of the lamp 11 the other terminal of which is connected by a gonductor 14 with the other contact meme1 4.

15 and 16 designate respectively two binding posts of the usual fuse block, the binding posts being respectively located in opposite sides of an electric circuit'which is being tested. In said sides of the circuit are also respectively located to other binding posts 17 and 18, which are respectively connected with'the binding posts 15 and 16 by conductors 19 and 20, in which are respectively located fuses 21 and 22.

To test a fuse plug, such as 7, it is fitted in the socket 6, and the contact members 3 and 4 are respectively held against the binding posts 15 and 16, as shown in Fig. 5, or against the posts 17 and 18. The current will then pass from the adjacent binding post to the contact member 3, and thence by conductor 12 to and through the fuse 8, if the latter is unbroken, thence through conductor 13 to and throu h the lamp 11, thence by conductor 14 to t e contact member 4 and thence to the binding post adjacent thereto, thereby lighting the lamp 11, which shows that the fuse is in operative condition.

To test a lamp, the fuse 8 being known to be sound, the lamp 11 is mounted in the socket 10, and the contact members 3 and 4 are applied to the binding posts 15 and 16, as above described. If the lamp does not light, it is defective.

Where there are a large number of fuse blocks in a house as in a large apartment house, a person can readily detect a defective fuse in one of the several fuse blocks, by testing each fuse block in the manner above described.

If the lamp does not light when the members 3 and 4 are touched to the posts 17 and 18, it indicates that the current is not reaching those posts. If the lamp lights when the contact members are touched to the posts 17 and 18, but does not light when the membersare touched to the posts 15 and 16, one of the fuses 21 or 22 is defective.

If it is desired to test a 220 volt circuit and the only lamps to be had are 110 voltage, two of these lamps may be respectively mounted in'the sockets 7 and 10 for testing purposes In testing with the device, the supporting member 1 1s so held that the member wil be between the'lamp 11 and the eyes of the operator. As the lamp 11 is at the side of the bracket 9 which is distant from the hand of the operator holding the handle 2, and as the bracket and supporting member are of insulating material, the face of the operator and the hand holding the tester will be protected from flying glass in case that the lamp breaks from the quantity of current passing through it.

We do not limit our invention to the structure shown and described, as many modifications within the scope of the ap- A circuit tester comprising a broad fiat I supporting member having at one end two armsrand at its other end a longitudinal handle, and having at one side between the handle and said arms a laterally extending bracket and at one side of said bracket an imperforate portion, two contacts on said arms respectively, two lamp socketsmounted one on said supporting member and adapted to receive a fuse, the other socket being mounted on the side of the bracket next to said imperforate portion and facing longitudinally withrespect to said supporting member and adapted tohold a lamp bulb at one side of and wholly between and parallel with the longitudinal edges of said supporting member, and adapted to-be covere by said imperforate portion, and conductive means connecting said sockets and said contacts.

In testimony whereof we have signed our names to this specification.

WILLIAM F. ROBINSON. FRANKLYN ROBINSON. 

